Motor controlled tension system for winding machine



July 10, 1956 L V, KElTl-l ET AL MOTOR CONTROLLED TENSION SYSTEM FOR WINDING MACHINE Filed July 8. 1955 3 Sheets-Sheet l SAVAGE AT TORNE Y July l0, 1956 J. v. KEITH ET AL MOTOR CONTROLLED TENSION SYSTEM FOR WINDING MACHINE Filed July 8, 1953 5 Sheets-Sheet 2 IIl INVENToRs JOHN V KEITH BY RICHARD AVAGE,

l l l A TTOPNE Y July 10, 1956 J. v. KEITH ET AL 2,754,459

MOTOR CONTROLLED TENSION SYSTEM FOR WINDING MACHINE Filed July 8, 1953 3 Sheets-Sheet 5 INVENroRs JOHN M KEITH BY RICHARD C. SAWGE A T TORNE Y MTR CGNTRLLED TENSION SYSTEM FR WMDING MACHINE V. Keith and Richard C. Savage, Warwick, R. I., assgnors et one-halt to Universal Winding Company, Cranston, R. l., a corporation of Massachusetts, one=halt` to General Electric Company, Schenectady, N. Y., a corporation of New York Application .lluiy 8, 1953, Serial No. 373,466

4 Claims. (Cl. 318-6) The present invention relates to winding machines and means for controlling the operation thereof, and more particularly relates to a winding machine and controls therefor for winding a strand of material made available at a substantially constant speed by a source of supply.

in the following specilication and claims the term yarn is employed in a general sense to apply to all kinds of strand materials, either textile or otherwise, and the designation package is intended to mean the product of a winding machine whatever its form.

It quite frequently becomes necessary in the manufac ture of textiles to wind a strand of yarn that is being continuously advanced at a substantially constant rate of speed. An example of such an operation is winding the output from a synthetic yarn spinning machine. In such a winding operation the yam must be wound at the same speed that it is advanced by the spinning machine, or other source of yarn supply, inasmuch as failure to do so would result in breaking the yarn if the Winder were to operate at a higher speed than the source of supply, or it' the Winder operates at a lower speed than said supply, cause a loop or" slack and tangled yarn to form between said Winder and said supply.

Many attempts have been made in the past to develop a winding machine capable of winding a strand of yarn that is continuously advancing at a substantially constant speed. Two examples of such prior art devices are disclosed in United States Patent No. 2,509,250 issued May 30, 1950 to l. S. Roberts, and United States Patent No. 2,608,355 issued August 26, 1952 to C. C. Bell et al. Eoth the Roberts device and the Bell et al. device include mechanisms, actuated by the tension in the strand of yarn being wound, to speed up and slow down the winding mechanism to cause it to keep pace with a continuously advancing strand of yarn. Both of these devices possess serious disadvantages that limit their use to comparatively heavy denier yarns and relatively low winding speeds inasmuch as the speed controlling mechanism in both structures require a large force to operate them and such a large force can only be applied by a heavy denier yarn. Furthermore, the reaction time of both the Roberts and Bell et al. control mechanisms is slow due to the inertia of the large masses necessary to control the winding speed thus limiting the use of these devices to applications where a slow winding speed is permissible.

it is, therefore, one object of the present invention to provide a winding machine capable of winding a continuously advancing small denier strand of yarn.

Another object of the present invention is to provide a winding machine capable of winding under light tension a strand of yarn that is continuously advancing at a substantially constant speed.

Anoher object of the present invention is to provide a winding machine capable of winding at high speed a small denier yarn that is continuously advancing at a constant rate of speed.

Another object of the present invention is to provide a winding machine capable of windingunder light tension Patented July 10, 1956 ice and at high speed a strand of yarn that is continuously advancing at a substantially constant speed.

Another object of the present invention is to provide a winding machine capable of winding under light tension a strand of yarn that is continuously advancing at a substantially constant speed and having means whereby the tension in the yarn controls the speed at which it is wound.

Another object of the present invention is to provide a winding machine capable of winding a small denier strand oi continuously advancing yarn and having means whereby the tension in the yarn controls the speed at which it is wound.

Another object of the present invention is to provide a winding machine wherein a light tension in the yarn being wound controls the electric current supplied the motor driving the winding machine to thereby control the speed at which said yarn is wound.

Another object of the present invention is to provide a winding machine wherein a light tension in the yarn being wound controls a relatively small electric current and the relatively small current controls the electric current supplied the motor driving the Winding machine to thereby control the speed at which said yarn is Wound.

Other objects will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement oi parts which are exemplified in the following detailed disclosure, and the scope of the application ot which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

Figure l is a front elevation of a winding machine incorporating a preferred embodiment of the present invennon;

Fig. 2 is a fragmentary sectional rear elevation showing the control mechanism of the present invention; and

Fig. 3 is a schematic wiring diagram of the control mechanism ol' the present invention.

Fig. l shows the winding mechanism designated generally as itil mounted on a pedestal or base 12. The winding mechanism 1d is of the type known in the art as a precision winder wherein the number of rotations of spindle 1d to each reciprocation of yarn guide 16 is xed from the start of the winding operation until the package being wound is completed. The winding mechanism shown comprises a spindle 14 rotatably journaled in a casing 18. The yarn guide 16 is mounted for reciprocation on transverse frame 2i) which in turn is mounted for pivotal movement on shaft 22 to permit said yarn guide 16 to move away from the spindle 14 as the yarn being wound thereon increases in diameter. Yarn guide 16 is connected to and reciprocated by a cam, not shown, located inside or" casing l. Spindle 14 is provided with an expansible and contractible package core holder 24 for releasably mounting package cores on said spindle. Operating handie 26 is provided for contracting package core holder 24 when it is desired to remove a full package from spindle 14 and replace it with an empty package core holder prior to commencing the winding or" the new package. All of the above described structure is old and Well known in the art and need not be described any further herein. Winding mechanism 10 is driven by an electric motor 28 mounted on bracket 29 secured to casing 18 and connected to the winding mechanism by any suitable means. Motor 2S is so wound that it has variable speed characteristics, that is to say, the speed of motor 28 increases or decreases as the electrical current supplied thereto is increased or decreased.

Referring now to Fig. 3 wherein is shown in schematic wiring diagram form the electrical circuit for driving mo tor 28 and for controlling the amount of current supplied said motor. Motor 28 is connected across alternating current supply lines 30 and 32. A normally closed single pole single throw switch 34, an adjustable resistor 36 and the load winding of a saturable reactor 38 are connected in series with motor 28 and said alternating current supply lines 30 and 32. The primary winding of a transformer 4t) is connected across alternating current supply lines 30 and 32 and the secondary of said transformer 4t) is connected by means of conductors il and 43 to the input of an electrical bridge 42. One arm or side of bridge 42 is formed by resistors 44 and 46, and the other arm or side of the bridge is formed by resistor 48 and reactor coil 50. The output of the bridge 42 is connected by means of conductors 52 and 54 to the input of a full wave rectifier 56. The output of rectier 56 is connected by conductors 58 and 60 to the control winding of saturable reactor 38. The inductance of reactor coil t) is adjustable by means of a core 62 of magnetic material which is adapted to be moved axially in and out of coil 5t). Alternating current supply lines 30 and 32 are provided with a double pole single throw switch 645 which functions as a main line on-otf switch for the circuit. For convenience in assembling the above described components in the apparatus, motor 28 is connected into the circuit by means of a plug P2 and socket S2 having respectively the male and female members P2a, P2b and S251, S211 and various other electrical components or groups of components are connected by means of multiple prong plug l and socket Sl having respectively the male and female members Pla, Plb, Plc, Pld and Sla, Sib, Sic, SIM.

The above described circuit functions in the following manner to control the speed of the motor 28. When switch 64 is closed electrical power flows through resistor 36, the load winding of saturable reactor 38, normally closed switch 34, and motor 28 to cause said motor to start and to drive winding mechanism 18. At the same time electrical current flows through the primary winding of transformer 46 causing a control voltage to be generated in the secondary winding of said transformer. When the effective resistance of resistors 44 and 46 are equal, and the effective resistance of resistor 48 and reactor coil 58 are equal no current will flow from the output terminals of the bridge. However, whenever this balance is upset by varying the impedance of reactor coil 58 by moving core 62 in or out of said coil a current will flow from bridge 42 to rectier 56 and the amount of current which flows will be proportional to the amount of imbalance present in the bridge. When bridge 42 is in an unbalance condition current flows therefrom through conductors 52 and 54 through rectifier 56 where it is rectified and the rectified current ows from the output of said rectifier, by means of conductors 58 and 64), and through the control winding of saturable reactor 38. One of the well known characteristics of a saturable reactor is that the ilow of current through the load winding thereof can be varied` by varying the flow of direct current through the control winding thereof. That is to say, the amount of current which can pass through the load winding of a saturable reactor increases within the limits of the reactor as the amount of current passing through the control winding is increased, and conversely the amount of current passing through the load winding decreases as the current passing through the control winding decreases. It is also a characteristic of saturable core reactors that relatively large amounts of current and relatively large changes in current flow, through the load winding thereof can be controlled by means of relatively small amounts of direct current passing through the control winding thereof. It will, therefore, be apparent that the speed of motor 28 can be controlled by moving core 62 into or out of reactor coil 50. It will also be apparent that the comparatively large amount of current needed to drive motor 28 can be effectively controlled by a relatively small current flowing through reactor coil 5t) and the control winding of saturable reactor 38. As a result the size of coil Si) and core 62 can be greatly reduced in size over those found necessary in prior art devices, and the small current iiow through coil 50 exerts only a relatively light magnetic pull on said core. Inasmuch as core 62 is moved relative to coil 50 by the yarn being wound, in a manner to be explained in detail hereinafter, it will be clear that the present invention makes it possible to wind a continuously advancing strand of yarn under light tension. It will also be clear that the lightness of core 62 and the small magnetic pull thereon permits said core to respond quickly to slight changes in tension in the winding strand of yarn therefore making it possible to wind a continuously advancing strand of yarn at a higher speed than had heretofore been possible.

Adjustable resistor 36 is utilized to preset the maximum amount of current which can ow through motor 28 to thereby preset the speed of said motor in the range of speed at which the winding mechanism must operate. The circuit of Fig. 3 is also provided with suitable safety devices, such as fuses and overload heaters; however, such safety devices are old and well known in the art and form no part of the present invention and, therefore, they have been omitted from the wiring diagram in the interests of simplicity.

Motor 28 has been disclosed hereinabove as being an alternating current motor, however, it will be understood that a direct current motor can be employed with the inclusion of a rectifier in the supply line between said motor and the load winding of the saturable reactor.

Referring now to Figs. l and 2, pedestal or base l2 is preferably fabricated from sheet metal and forms a hollow cabinet or enclosure having an opening 66 formed in its front. A panel 68 serves as a closure for opening 66 and is removably held in position thereover by any convenient fastening means as, for example, screws 70. Panel 68 has many of the electrical components included in the circuit disclosed in Fig. 3 mounted thereon and it also carries the mechanism for moving core 62 axially of reactor coil 50. When viewed from its inner or back side, Fig. 2, panel 68 preferably has reactor coil Sti mounted adjacent its lower left hand corner by means of mounting bracket '72. The components comprising saturable reactor 38, full wave rectifier 56 and resistors 4d, 46 and 48 of bridge 42 and socket S2 may be located on panel 68 in any convenient manner. Transformer 4i? and resistor 36 may be located in pedestal or base 12 in any convenient location and connected to the components on panel 68 by means of multiple prong plug Pl and socket S1 (not shown). In the event the winding mechanism of the present invention is incorporated in a gang machine, or multiple head machine, wherein a plurality of similar winding units are mounted side by side one transformer 46 may be utilized to supply a control voltage for all of the winding units and one resistor 36 may be utilized to preset the maximum speed of all of the motors in the gang as a unit. It will be obvious that some other method or device can be substituted for resistor 36 to determine the maximum voltage that can be impressed on motors 28 to preset their maximum speed. In such event a single transformer 4t) and resistor 36 can be mounted in any convenient location, preferably at one end of the gang machine and connected by suitable conductors to socket S1 located adjacent each panel 68.

A wheel 74 is rotatably mounted above coil 58 with its periphery substantially tangent to the axis of said coil by being fixed to a shaft 76 which extends through and is rotatably journaled in panel 68. Core 62 is connected to wheel 74 by means of a ilexible tape 78 secured at one of its ends to the periphery of wheel 74 and having its other end secured to one end of core 62 whereby rotation of said wheel will raise and lower said core thereby causawstats ing it to move into or out of the axial opening in coil 50. A compensator arm 80 is fixed adjacent one of its ends to the end of shaft 76 projecting from the face of panel 63 and carries a dancer roll h2 at its other end. Dancer roll S2 is adapted to engage a loop formed in the running strand of yarn Y between an idler roll 84 and yarn guide 16 so that an increase in tension in yarn Y will lift said dancer roll to rotate wheel 74 in a direction to lower core 62 into coil 5l). Movement of core 62 into coil 50 increases the impedance of said coil and tends to bring the two arms of bridge 42 more nearly into balance thereby decreasing the flow of current through conductors 52 and 54 and through the control winding of saturable reactor 3% thereby causing said saturable reactor to restrict the current flowing through its load winding and consequently causing motor 28 to slow down. Conversely a decrease in tension in strand Y permits dancer roll 82 to move downwardly permitting wheel 74 to rotate in a direction to lift core 62 out of coil 50 thereby throwing the two arms of bridge 42 out of balance to an increasingly greater degree as said roll descends resulting in more current iiowing through conductors 52 and S4 and the control winding of saturable reactor 38 whereby said saturable reactor permits more current to iiow through its load winding to thereby speed up motor 28 and the Winder.

As core 62 moves from a position wherein the major portion of its length is outside of coil 50 to a position wherein it is substantially centered in said coil the magnetic attraction on said core lirst increases, reaching a maximum when said core is half way in said coil, and then decreases to a minimum when the core is centered in the coil. To compensate for this variation in the magnetic attraction on core 62, which obviously is transmitted to wheel 74 and dancer roll 32 through ilexible tape 7S, spring means are provided. The compensating spring means comprises a helical tension spring S6 having one of its ends secured to a pin 8S, located beneath shaft 76, and its other end secured to a pin 9i) carried by the hub 91 of wheel 74. It will be seen, therefore, that as wheel 7d rotates from the position wherein core 62 is substantially removed from coil 56 to the position wherein said core is substantially centered in said coil, spring S6 will act on said wheel to oppose the magnetic attraction on core 62. it will be noted that the effective morent arm through which spring 86 acts on wheel 74, i. e. the horizontal distance from pin 90 to a vertical line passing through the axis of shaft 76, will increase and then decrease as pin 9G moves from its lowermost position to its uppermost position. The tension of spring 86 and the radial distance of pin 9i) from the axis of wheel 74 are such that the turning moments exerted on shaft 7e by the magnetic attraction on core 62 and by spring Se are substantially equal at all times.

Resilient means in the form of spring 92 is provided to compensate for the weight of core 62 and to provide a force tending to draw said core out of coil Si?. One end of spring 92 is secured to a length of flexible tape 941 which in turn is secured to the periphery of hub 91. The other end of spring 92 is secured to one end of arm 96 and the other end of said arm is lixedly attached to shaft 93 which is rotatably journaled in and extends through front wall of pedestal 12. A second arm 160 has one of its ends xedly secured to the outer end of shaft 9S so that arms 96 and 100 and shaft 98 act as a lever pivoting around shaft 98. It will be seen that pivotal movement of a-rm 96 in a counterclockwise direction, as viewed in Fig. 2, will reduce the tension spring 92 exerts on ywheel 74. That is to say, that swinging movement of arm 96 in a counterclockwise direction reduces lthe force tending to draw core 62 out of coil 50 with the result that less tension is then required in the strand of yarn Y to move said core into the coil, or to maintain it therein. Spring 92 preferably is of considerable length and the diameter of hub 91 is small with the result that movement of compensator arm to raise or lower core 62 extends or contracts said spring only a small percentage of its total movement and, therefore, does not change to an appreciable degree the force eX- erted by said spring on said compensator arm. A lever 192 is pivotally mounted at one of its ends to the face of casing 1S and is connected by means of link 194 to traverse frame 2t?. The free end of lever 102 carries a weight 136 that can be prepositioned thereon and which tend-s to rotate lever 162 in a counterclockwise direction, as viewed in Fig. l, to thereby maintain yarn guide 16 in contact with the periphery of the package of yarn being wound on spindle 14. The free end of arm 1641 is connected to lever 162 by means of link 103 so that the swinging movement of t-raverse frame 20, resulting from the growth of the package of yarn being wound, will lift the free end of arm 1% to thereby lower arm 96 to thereby reduce the force exerted by spring 92 on 4wheel 74. The free end of arm lili) and the lowermost end of link 1655 are provided with a plurality of holes and 112 respectively to make it possible to preset the maximum amount of tension exerted by spring 92 and to preset the maximum amount of turning movement which traverse frame 2@ can impart to the arms 96 and 100.

The normally closed single pole single throw switch 34 is located on the inner surface of panel 63 adjacent shaft 76 and is positioned to have projecting linger 113 carried by its actuating arm 114 engaged by the spoke 116 of wheel 741 to open said switch in the event strand of yarn Y breaks to stop motor 2S and the operation of the winding mechanism.

The above described mechanism operates in the following manner. The 4strand of yarn Y being fed at a substantially constant speed passes over idler roll 84, under dancer roll 32 and up to yarn guide 16 and the package core carried by spindle 14 to form a loop of yarn which supports compensator arm 8%. Winding of the strand of yarn Y by spindle 14 -tends to shorten the loop of yarn supporting compensator arm 80 to lift said arm to rotate wheel 74 in a counterclockwise direction, as viewed in Fig. 2, to lower core 62 into coil 50 thereby increasing the impedance of said coil and as a result reducing the amount of current flowing from `bridge 42 through rectifier 56 and through the control winding of saturable reactor 38. As a result the amount of current passing through the load winding of said saturable reactor is reduced thereby causing motor 28 and spindle 14 to slow down. Compensator arm 80 will continue to rise until such time as spindle 14 is winding yarn Y at the same speed that it is being advanced. in the event spindle 1f@ winds yarn Y at a slower speed than it is being advanced, the loop will increase in size lowering compensator arm @d to -thereby draw core 62 out of coil 50 whereupon a larger current will ow from bridge 42 with the result that motor 2S and spindle 14 will be speeded up until such time as said spindle is again winding the yarn at the same speed that it is being advanced. In the event strand of yarn Y breaks or is exhausted spring 9.?. will rotate wheel 74 in a clockwise direction, as viewed in Fig. 2, until spoke 116 contacts linger 113 of switch 31tto open said switch and stop the operation of motor 28.

Obviously, the tension which will be imparted to the yarn by the winding operation is controlled by the force compensator arm 8@ and dancer roll 82 exert upon said yarn, and 'this force is a combination of the weight of arm Si) and roll S2 and the force imposed thereon by spring 92. rhe force imposed by spring 92 can be adjusted to predetermine the tension which will ybe imparted to the winding yarn by raising or lowering arm 96 by using appropriate holes 112 to connect arm 100 to link 108.

As the package being wound increases in diameter traverse frame 2i) is pivoted, by the growing package, around shaft 22. This pivoting movement causes said traverse frame 2l) to lift links 194 and 108 which are connected to arm 100 to lift said arm and thereby lower arm 96. Lowering arm 96 reduces the tension in spring 92. It will, therefore, be seen that the tension under which strand of yarn Y is wound will gradually decrease from the start to finish of each package wound. The amount by which the tension in strand Y is reduced can be adjusted to a predetermined range by the selection of the appropriate hole 110 in arm M0 to use to connect said arm to link 108.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. In a winding machine having a rotatable winding spindle and means for traversing a running strand of yarn across a predetermined length of said spindle, the combination comprising an alternating current electric motor having Variable speed characteristics for rotating said spindle, an alternating current supply line for driving said motor, a saturable reactor having a load winding and a control winding, said load winding being connected in series with said motor and said supply line, means adapted to engage said strand of yarn prior to its being engaged by said traversing means and to move in response to lchanges in tension therein, a source of direct current including a current regulating bridge and an unregulated rec'tifier, the output of said bridge being connected to said rectifier and the output of said rectifier being connected to said control winding whereby the power output of said bridge is rectified and fed to said control winding, and means for controlling the output of said -bridge to thereby control the amount of current flowing through said load winding and said motor to thereby control the speed of said motor, said controlling means comprising a reactor coil included in one side of said bridge, a core of magnetic material movable axially into and out of said coil, said core and said yarn engaging means being Iconnected whereby movement of said yarn engaging means in response to an increase or decrease in yarn tension moves said core into or out of said coil, and compensating means for applying a torque to said yarn engaging means substantially equal and opposite to the torque exerted thereon by the magnetic attraction of said coil on said core and the weight of the core.

2. In a winding machine having a rotatable winding spindle and means for traversing a running strand of yarn across a predetermined length of said spindle, the combination comprising an alternating current electric motor having variable speed characteristics for rotating said spindle, an alternating current supply line for driving said motor, a saturable reactor having a load winding and a control winding, said load winding being connected in series with said motor and said supply line, means adapted yto be engaged by said strand of yarn prior to its being engaged by said traversing means and to be moved thereby in one direction when the tension therein exceeds a predetermined value, means applying a fonce opposing movement of said yarn engaging means in said one direction for moving it in the opposite direction when the ltension in said strand of yarn is less than said predetermined value, a source of direct current including a current regulating bridge and an unregulated rectifier, the output of 'said bridge being connected to said rectifier and the output of said rectifier being connected to said control winding whereby the power output of said bridge is rectified and fed to said control winding, and means for -controlling the output of said bridge to thereby control the amount of current flowing through said load winding and said motor to thereby control the speed of said motor, said controlling means comprising a reactor coil included in one side of said bridge, a core of magnetic material movable axially into and out of said coil, said core and said yarn engaging means being connec-ted whereby movement of said yarn engaging means in response to an increase or decrease in yarn tension moves said core into or out of said coil, and means for decreasing said force as the package being wound increases in diameter.

3. In a winding machine having a rota-table winding spindle and means for traversing a running strand of yarn across a predetermined length of said spindle, the combination comprising an alternating current electric motor having variable speed characteristics for rotating said spindle, an alternating current supply line for driving said motor, a saturable reactor'having a load winding and a control winding, said load winding being connected in series with said motor and said supply line, means adapted to engage said strand of yarn prior to its being engaged by said traversing means and to move in response to changes in tension therein, a source of direct current including a current regulating bridge and an unregulated rectifier, the ou-tput of said bridge being connected to said rectifier for rectification thereby and the output of said rectifier being connected to said control winding whereby the power output of said bridge is rectified and fed -to said control winding, and means for controlling the output of said bridge to thereby control the amount of current owing through said load winding and said motor to thereby control the speed of said motor, said controlling means comprising a reactor coil included in one side of said bridge, a core of magnetic material movable axially into and out of said coil, said core and said yarn engaging means being connected whereby movement of said yarn engaging means in response to an increase or decrease in yarn tension moves said core into or out of said coil.

4. In a winding machine having a rotatable winding spindle and means for traversing a running strand of yarn across a predetermined length of said spindle, the combination comprising an alternating current electric motor having variable speed characteristics for rotating said spindle, an alternating current supply line for driving said motor, a satur-able reactor having a load winding and a control winding, said load `winding being connected in series with said motor and said supply line, means adapted to engage said strand of yarn prior to its being engaged by said traversing means and to move in response to changes in tension therein, a source of direct current including a current regulating bridge and an unregulated rectiiier, the output of said bridge being connected to said rectifier for rectification thereby and the output of said rectifier being connected `to said control winding whereby the power output of said bridge is rectified and fed to said control winding, and means for controlling the output of said bridge to thereby control the amount of current flowing through said load winding and said motor to thereby control the speed of said motor, said controlling means comprising an adjustable element in said bridge adjustable by movement of said yarn engaging means whereby movement thereof in response to an increase or decrease in yarn tension changes the condition of said bridge.

References Cited in the file of this patent UNITED STATES PATENTS 2,032,176 Kovalsky Feb. 25, 1936 '2,116,586 Stoller May 10, 1938 2,140,555 Satterlee Dec. 20, 1938 2,146,869 White Feb. 14, 1939 2,509,250 Roberts May 30, 1950 2,608,355 Bell et al Aug. 26, 1952 

